The invention is based on a sanitary fitting including a mixer valve, more particularly, a thermostat.
Thermostatic valves have two actuating elements, namely one element for adjusting the temperature with the aid of the thermostat and a second actuating element for opening and closing the valve leading to the discharge. In this arrangement it is often so that the thermostat is set once only, it then remaining always at the same temperature for a long time.
For selecting water discharge, for example between a bathtub tap and a hand shower a further actuating element is usually provided which may be applied to the fitting itself or also remote therefrom.
To simplify use thereof it is already known (EP-A-246 405) to configure a sanitary fitting so that the flow control valve which controls the amount of mixed water coming from the thermostat is also used for selecting the two discharge points. In this case, however, there is a crossflow risk, i.e. water gaining access, for example, from the cold water pipe into the hot water pipe. To prevent this happening backflow preventers need to be inserted upstream of the thermostatic valve.
It is also known to arrange a separate shutoff valve for each hot and cold water pipe upstream of a thermostat and to actuate the two separate shutoff valves via a common positioning control element. However, since the two shutoff valves cannot be precisely tuned to each other a slipping clutch needs to be incorporated between the common actuating element and each of the two shutoff valves. This may result in the user experiencing a significantly increased resistance in a certain position when closing the valve, prompting him to wrongly assume that the valve is closed. Instead, this increased resistance merely signifies that one of the two valves is closed whilst the other is still open.